Due to diversified needs in recent years, there has been increasing demand for low-volume high-variety production by injection molding, and the frequency of change in a mold used in an injection molding machine tends to increase.
Molds need to be accurately fixed to the injection molding machine even they are heavy in weight. Accordingly, the fixation of molds is time-consuming work for even skilled workers.
To facilitate mold changing, Patent Document 1 discloses a method in which a mold change device is provided on a side surface of a horizontal injection molding machine.
Patent document 1: JP H9-66543 A
According to Patent Document 1, a large number of rollers is installed to place a mold on the mold attachment surfaces of the mold change device and the molding machine so that the mold is can be conveyed by the rotation of the rollers.
Molds of various sizes are used in the same molding machine, and they may have a larger weight difference three times or more in some cases.
In a horizontal injection molding machine, it is necessary to align the position of a nozzle touch portion of the mold with the position of an injection nozzle of the injection molding machine. Accordingly, the vertical position of the mold needs to be kept within a certain range regardless of the weight of the mold.
Therefore, according to the conventional technique disclosed in Patent Document 1, the rollers are rotatably fixed in predetermined positions.